The Support Package includes static "support libraries" that you can add to your Android application in order to use APIs that are either not available for older platform versions or that offer "utility" APIs that aren't a part of the framework APIs.

The YUI Compressor is a JavaScript compressor which, in addition to removing
comments and white-spaces, obfuscates local variables using the smallest
possible variable name. This obfuscation is safe, even when using constructs
such as 'eval' or 'with' (although the compression is not optimal is those
cases) Compared to jsmin, the average savings is around 20%.